Ever since middle school my sister Wang Wei and I ____ ____ ____ ____ a great bike trip.
唐法典《仪制令》规定:“行路,贱避贵,来避去,少避老,轻避重,违者笞五十”,这表明唐朝时( )
不为0的四个实数a、b,c、d满足ab=cd,改写成比例式错误的是( )